Factors associated with diagnostic ultrasound for midgut volvulus and relevance of the non-diagnostic examination.

BACKGROUND: Few reports explore the frequency and factors associated with diagnostic ultrasound (US) for midgut volvulus. OBJECTIVE: To evaluate predictive factors for diagnostic US for midgut volvulus and clinical outcomes of patients with non-diagnostic US. MATERIALS AND METHODS: This retrospective study included infants imaged for midgut volvulus with US. Exams were rated as diagnostic (midgut volvulus present or absent) or non-diagnostic by a pediatric radiologist, and in cases of disagreement with the original report, an additional pediatric radiologist was the tie-breaker. For each exam, the following were recorded: age, weight, respiratory support, exam indication, sonographer experience, and gaseous dilated bowel loops on radiography. Logistic regression models with "stepwise" variable selection were used to investigate the association of diagnostic US for midgut volvulus with each of the independent variables. RESULTS: One hundred nineteen patients were imaged. US was diagnostic in 74% (88/119) of patients. In subsets of patients presenting with bilious emesis or age <28 days, US was diagnostic in 92% (22/24) and 90% (53/59), respectively. Logistic regression suggested that symptom type (bilious vs other) was the best predictor of diagnostic US (type 3 P=0.02). Out of 26 patients with available radiographs, US was diagnostic in 92% (12/13) of patients without bowel dilation on radiographs compared to 62% (8/13) of patients with bowel dilation (P=0.16). Weight, respiratory support, and sonographer experience did not differ between groups. Two sick neonates, ages 2 days and 30 days, in whom the primary clinical concern was dropping hematocrit and sepsis, respectively, had non-diagnostic ultrasounds in the setting of bowel dilation on radiography. Both were found to have midgut volvulus at surgery and both expired. CONCLUSION: US was most frequently diagnostic in patients with bilious emesis or age less than 28 days. Non-diagnostic US for midgut volvulus must prompt a predetermined follow-up strategy, such as an additional imaging study (e.g., upper GI series), particularly in a sick child, as non-diagnostic US may miss midgut volvulus.

Imaging of pediatric ovarian tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Ovarian tumors in children are uncommon. Like those arising in the adult population, they may be broadly divided into germ cell, sex cord, and surface epithelium subtypes; however, germ cell tumors comprise the majority of lesions in children, whereas tumors of surface epithelial origin predominate in adults. Diagnostic workup, including the use of imaging, requires an approach that often differs from that required in an adult. This paper offers consensus recommendations for imaging of pediatric patients with a known or suspected primary ovarian malignancy at diagnosis and during follow-up.

Imaging of pediatric testicular tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Primary intratesticular tumors are uncommon in children, but incidence and risk of malignancy both sharply increase during adolescence. Ultrasound is the mainstay for imaging the primary lesion, and cross-sectional modalities are often required for evaluation of regional or distant disease. However, variations to this approach are dictated by additional clinical and imaging nuances. This paper offers consensus recommendations for imaging of pediatric patients with a known or suspected primary testicular malignancy at diagnosis and during follow-up.

Congenital lung lesions: a radiographic pattern approach.

Congenital lung malformations represent a spectrum of abnormalities that can overlap in imaging appearance and frequently coexist in the same child. Imaging diagnosis in the neonatal period can be challenging; however, the recognition of several archetypal radiographic patterns can aid in narrowing the differential diagnosis. Major radiographic archetypes include (1) hyperlucent lung, (2) pulmonary cysts, (3) focal opacity and (4) normal radiograph. Here we review the multimodality imaging appearances of the most commonly seen congenital lung malformations, categorized by their primary imaging archetypes. Along with the congenital lung malformations, we present several important imaging mimickers.

Artificial Intelligence Algorithm Improves Radiologist Performance in Skeletal Age Assessment: A Prospective Multicenter Randomized Controlled Trial.

Background Previous studies suggest that use of artificial intelligence (AI) algorithms as diagnostic aids may improve the quality of skeletal age assessment, though these studies lack evidence from clinical practice. Purpose To compare the accuracy and interpretation time of skeletal age assessment on hand radiograph examinations with and without the use of an AI algorithm as a diagnostic aid. Materials and Methods In this prospective randomized controlled trial, the accuracy of skeletal age assessment on hand radiograph examinations was performed with (n = 792) and without (n = 739) the AI algorithm as a diagnostic aid. For examinations with the AI algorithm, the radiologist was shown the AI interpretation as part of their routine clinical work and was permitted to accept or modify it. Hand radiographs were interpreted by 93 radiologists from six centers. The primary efficacy outcome was the mean absolute difference between the skeletal age dictated into the radiologists' signed report and the average interpretation of a panel of four radiologists not using a diagnostic aid. The secondary outcome was the interpretation time. A linear mixed-effects regression model with random center- and radiologist-level effects was used to compare the two experimental groups. Results Overall mean absolute difference was lower when radiologists used the AI algorithm compared with when they did not (5.36 months vs 5.95 months; P = .04). The proportions at which the absolute difference exceeded 12 months (9.3% vs 13.0%, P = .02) and 24 months (0.5% vs 1.8%, P = .02) were lower with the AI algorithm than without it. Median radiologist interpretation time was lower with the AI algorithm than without it (102 seconds vs 142 seconds, P = .001). Conclusion Use of an artificial intelligence algorithm improved skeletal age assessment accuracy and reduced interpretation times for radiologists, although differences were observed between centers. Clinical trial registration no. NCT03530098 © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Rubin in this issue.

Medical Student Engagement and Educational Value of a Remote Clinical Radiology Learning Environment: Creation of Virtual Read-Out Sessions in Response to the COVID-19 Pandemic.

RATIONALE AND OBJECTIVES: The need for social distancing has resulted in rapid restructuring of medical student education in radiology. While students traditionally spend time learning in the reading room, remote clinical learning requires material shared without direct teaching at the radiology workstation. Can remote clinical learning meet or exceed the educational value of the traditional in-person learning experience? Can student engagement be matched or exceeded in a remote learning environment? MATERIALS AND METHODS: To replace the in-person reading room experience, a small-group learning session for medical students named Virtual Read-Out (VRO) was developed using teleconferencing software. After Institutional Review Board approval, two student groups were anonymously surveyed to assess differences in student engagement and perceived value between learning environments: "Conventional" students participating in the reading room (before the pandemic) and "Remote" students participating in VRO sessions. Students reported perceived frequency of a series of five-point Likert statements. Based on number of respondents, an independent t-test was performed to determine the significance of results between two groups. RESULTS: Twenty-seven conventional and 41 remote students responded. Remote students reported modest but significantly higher frequency of active participation in reviewing radiology exams (p < 0.05). There was significantly lower frequency of reported boredom among Remote students (p < 0.05). There was no significant difference in perceived educational value between the two groups. CONCLUSION: Students report a high degree of teaching quality, clinical relevance, and educational value regardless of remote or in-person learning format. Remote clinical radiology education can be achieved with equal or greater student interaction and perceived value in fewer contact hours than conventional learning in the reading room.

Impact on Participants of Family Connect, a Novel Program Linking COVID-19 Inpatients' Families With the Frontline Providers.

PURPOSE: With clinical volumes decreased, radiologists volunteered to participate virtually in daily clinical rounds and provide communication between frontline physicians and patients with coronavirus disease 2019 (COVID-19) and their families affected by restrictive hospital visitation policies. The purpose of this survey-based assessment was to demonstrate the beneficial effects of radiologist engagement during this pandemic and potentially in future crises if needed. METHODS: After the program's completion, a survey consisting of 13 multiple-choice and open-ended questions was distributed to the 69 radiologists who volunteered for a minimum of 7 days. The survey focused on how the experience would change future practice, the nature of interaction with medical students, and the motivation for volunteering. The electronic medical record system identified the patients who tested positive for or were suspected of having COVID-19 and the number of notes documenting family communication. RESULTS: In all, 69 radiologists signed or cosigned 7,027 notes. Of the 69 radiologists, 60 (87.0%) responded to the survey. All found the experience increased their understanding of COVID-19 and its effect on the health care system. Overall, 59.6% agreed that participation would result in future change in communication with patients and their families. Nearly all (98.1%) who worked with medical students agreed that their experience with medical students was rewarding. A majority (82.7%) chose to participate as a way to provide service to the patient population. CONCLUSION: This program provided support to frontline inpatient teams while also positively affecting the radiologist participants. If a similar situation arises in the future, this communication tool could be redeployed, especially with the collaboration of medical students.

Ovarian neoplasms of childhood.

Ovarian neoplasms are rare in children. Although usually asymptomatic, they sometimes present with abdominal pain, abdominal distension or palpable mass. The distribution of neoplasms in the pediatric population is different from in adults; benign mature cystic teratoma is the most common ovarian tumor in children. Radiologists should be familiar with the variable sonographic, CT and MRI findings of ovarian neoplasms. Although the less frequently encountered ovarian malignancies cannot be reliably distinguished by imaging alone, it does play an important role in workup. This review discusses the imaging and relevant clinical manifestations of the more commonly encountered pediatric ovarian neoplasms.

Visualization of the normal appendix in children: feasibility of a single contrast-enhanced radial gradient recalled echo MRI sequence.

BACKGROUND: Magnetic resonance imaging (MRI) assessment for appendicitis is limited by exam time and patient cooperation. The radially sampled 3-dimensional (3-D) T1-weighted, gradient recalled echo sequence (radial GRE) is a free-breathing, motion robust sequence that may be useful in evaluating appendicitis in children. OBJECTIVE: To compare the rate of detection of the normal appendix with contrast-enhanced radial GRE versus contrast-enhanced 3-D GRE and a multi-sequence study including contrast-enhanced radial GRE. MATERIALS AND METHODS: This was a retrospective study of patients ages 7-18 years undergoing abdominal-pelvic contrast-enhanced MRI between Jan. 1, 2012, and April 1, 2016. Visualization of the appendix was assessed by consensus between two pediatric radiologists. The rate of detection of the appendix for each sequence and combination of sequences was compared using a McNemar test. RESULTS: The rate of detection of the normal appendix on contrast-enhanced radial GRE was significantly higher than on contrast-enhanced 3-D GRE (76% vs. 57.3%, P=0.003). The rate of detection of the normal appendix with multi-sequence MRI including contrast-enhanced radial GRE was significantly higher than on contrast-enhanced 3-D GRE (81.3% vs. 57%, P<0.001). There was no significant difference between the rate of detection of the normal appendix on contrast-enhanced radial GRE alone and multi-sequence MRI including contrast-enhanced radial GRE (76% vs. 81.3%, P=0.267). CONCLUSION: Contrast-enhanced radial GRE allows superior detection of the normal appendix compared to contrast-enhanced 3-D GRE. The rate of detection of the normal appendix on contrast-enhanced radial GRE alone is nearly as good as when the contrast-enhanced radial GRE is interpreted with additional sequences.

Comparison of hybrid 18F-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging and positron emission tomography/computed tomography for evaluation of peripheral nerve sheath tumors in patients with neurofibromatosis type 1.

Rapidly enlarging, painful plexiform neurofibromas (PN) in neurofibromatosis type 1 (NF1) patients are at higher risk for harboring a malignant peripheral nerve sheath tumor (MPNST). Fludeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) has been used to support more invasive diagnostic and therapeutic interventions. However, PET/CT imparts an untoward radiation hazard to this population with tumor suppressor gene impairment. The use of FDG PET coupled with magnetic resonance imaging (MRI) rather than CT is a safer alternative but its relative diagnostic sensitivity requires verification. Ten patients (6 females, 4 males, mean age 27 years, range 8-54) with NF1 and progressive PN were accrued from our institutional NF Clinic. Indications for PET scanning included increasing pain and/or progressive disability associated with an enlarging PN on serial MRIs. Following a clinically indicated whole-body FDG PET/CT, a contemporaneous PET/MRI was obtained using residual FDG activity with an average time interval of 3-4 h FDG-avid lesions were assessed for both maximum standardized uptake value (SUVmax) from PET/CT and SUVmax from PET/MR and correlation was made between the two parameters. 26 FDG avid lesions were detected on both PET/CT and PET/MR with an accuracy of 100%. SUVmax values ranged from 1.4-10.8 for PET/CT and from 0.2-5.9 for PET/MRI. SUVmax values from both modalities demonstrated positive correlation (r = 0.45, P < 0.001). PET/MRI radiation dose was significantly lower (53.35% ± 14.37% [P = 0.006]). In conclusion, PET/MRI is a feasible alternative to PET/CT in patients with NF1 when screening for the potential occurrence of MPNST. Reduction in radiation exposure approaches 50% compared to PET/CT.

Interstitial nephritis: Two pediatric cases with atypical radiological features.

Interstitial nephritis (IN) is a relatively rare entity in children and adolescents that can be caused by a range of disorders including infection, medications, inflammatory bowel disease, and sarcoid. There is no proven therapy for this condition. We present 2 cases of biopsy-proven interstitial nephritis, of which 1 case was with granulomatous features that presented with unusual sonographic findings of discrete mass lesions in the kidney parenchyma bilaterally. Although a precise cause could not be identified in either case, 1 patient progressed to end-stage kidney disease (ESKD) and the other is in the early stages of treatment. We suggest that recognition of the atypical imaging features of interstitial nephritis may enable early recognition of this condition and avoid confusion with neoplastic or infectious processes.

Fetal and Postnatal Magnetic Resonance Imaging of Unilateral Cystic Renal Dysplasia in a Neonate with Tuberous Sclerosis.

Tuberous sclerosis (TS) is an autosomal dominant condition associated with mutations in the TSC1 and/or TSC2 genes. Clinical manifestations are multisystemic, and they often include lesions in the brain, skin, heart, kidneys, and bones. TSC2 gene mutations can be seen concomitantly with autosomal dominant polycystic kidney disease gene mutations. We present a case of a fetus with prenatal diagnosis of TS that had unique asymmetrical distribution of renal cystic disease. We describe the extensive work up with both fetal and neonatal magnetic resonance imaging with correlating images of the unilateral polycystic renal disease in addition to typical TS brain findings.

Recurrent Pelvic Infections and Salpingitis after Perforated Appendicitis.

BACKGROUND: The effect of perforated appendicitis on the adnexa is an issue of concern and controversy. Long-term fertility studies have been conflicting. CASE: We present the case of a patient with chronic pelvic infections, salpingitis, and hydrosalpinx after perforated appendicitis. SUMMARY AND CONCLUSION: Magnetic resonance imaging was helpful in diagnosing a chronically obstructed fallopian tube, likely secondary to the dense adhesions from her previously treated perforated appendicitis. Salpingectomy relieved her symptoms of chronic pain and recurrent infections.

High Spatiotemporal Resolution Dynamic Contrast-Enhanced MR Enterography in Crohn Disease Terminal Ileitis Using Continuous Golden-Angle Radial Sampling, Compressed Sensing, and Parallel Imaging.

OBJECTIVE: The purpose of this article was to assess the feasibility of golden-angle radial acquisition with compress sensing reconstruction (Golden-angle RAdial Sparse Parallel [GRASP]) for acquiring high temporal resolution data for pharmacokinetic modeling while maintaining high image quality in patients with Crohn disease terminal ileitis. MATERIALS AND METHODS: Fourteen patients with biopsy-proven Crohn terminal ileitis were scanned using both contrast-enhanced GRASP and Cartesian breath-hold (volume-interpolated breath-hold examination [VIBE]) acquisitions. GRASP data were reconstructed with 2.4-second temporal resolution and fitted to the generalized kinetic model using an individualized arterial input function to derive the volume transfer coefficient (K(trans)) and interstitial volume (v(e)). Reconstructions, including data from the entire GRASP acquisition and Cartesian VIBE acquisitions, were rated for image quality, artifact, and detection of typical Crohn ileitis features. RESULTS: Inflamed loops of ileum had significantly higher K(trans) (3.36 ± 2.49 vs 0.86 ± 0.49 min(-1), p < 0.005) and v(e) (0.53 ± 0.15 vs 0.20 ± 0.11, p < 0.005) compared with normal bowel loops. There were no significant differences between GRASP and Cartesian VIBE for overall image quality (p = 0.180) or detection of Crohn ileitis features, although streak artifact was worse with the GRASP acquisition (p = 0.001). CONCLUSION: High temporal resolution data for pharmacokinetic modeling and high spatial resolution data for morphologic image analysis can be achieved in the same acquisition using GRASP.

Spontaneous Regression of Thoracic and Extraperitoneal Glial Implants in Child With Gliomatosis Peritonei After Resection of Ovarian Teratoma.

Gliomatosis peritonei is a rare condition associated with ovarian teratomas. Even rarer is extraperitoneal gliomatosis. We present a case of extraperitoneal gliomatosis with pleural implants and implants within the flank muscles, which regressed after resection of the primary tumor.

The challenging ultrasound diagnosis of perforated appendicitis in children: constellations of sonographic findings improve specificity.

BACKGROUND: Rapid and accurate diagnosis of appendicitis, particularly with respect to the presence or absence of perforation, is essential in guiding appropriate management. Although many studies have explored sonographic findings associated with acute appendicitis, few investigations discuss specific signs that can reliably differentiate perforated appendicitis from acute appendicitis prior to abscess formation. OBJECTIVE: The purpose of our study was to identify sonographic findings that improve the specificity of US in the diagnosis of perforated appendicitis. Our assessment of hepatic periportal echogenicity, detailed analysis of intraperitoneal fluid, and formulation of select constellations of sonographic findings expands upon the literature addressing this important diagnostic challenge. MATERIALS AND METHODS: We retrospectively reviewed 116 abdominal US examinations for evaluation of abdominal pain in children ages 2 to 18 years from January 2008 to September 2011 at a university hospital pediatric radiology department. The study group consisted of surgical and pathology proven acute appendicitis (n = 51) and perforated appendicitis (n = 22) US exams. US exams without a sonographic diagnosis of appendicitis (n = 43) confirmed by follow-up verbal communication were included in the study population as the control group. After de-identification, the US exams were independently reviewed on a PACS workstation by four pediatric radiologists blinded to diagnosis and all clinical information. We recorded the presence of normal or abnormal appendix, appendicolith, appendiceal wall vascularity, thick-walled bowel, dilated bowel, right lower quadrant (RLQ) echogenic fat, increased hepatic periportal echogenicity, bladder debris and abscess or loculated fluid. We also recorded the characteristics of intraperitoneal fluid, indicating the relative quantity (number of abdominal regions) and quality of the fluid (simple fluid or complex fluid). We used logistic regression for correlated data to evaluate the association of diagnosis with the presence versus absence of each US finding. We conducted multivariable analysis to identify constellations of sonographic findings that were predictive of perforated appendicitis. RESULTS: The individual US findings of abscess/loculated fluid, appendicolith, dilated bowel and increased hepatic periportal echogenicity were significantly associated with perforated appendicitis when compared with acute appendicitis (P < 0.01). The sonographic observation of increased hepatic periportal echogenicity demonstrated a statistically significant association with perforated appendicitis compared with acute appendicitis (P < 0.01). The presence of complex fluid yielded a specificity of 87.7% for perforated appendicitis compared with the acute appendicitis group. The US findings of ≥2 regions or ≥3 regions with fluid had specificity of 87.3% and 99.0%, respectively, for perforated appendicitis compared with the acute appendicitis group. Select combinations of sonographic findings yielded high specificity in the diagnosis of perforated appendicitis compared with acute appendicitis. These constellations yielded higher specificity than that of each individual finding in isolation. The constellation of dilated bowel, RLQ echogenic fat, and complex fluid had the highest specificity (99.5%) for perforated appendicitis (P < 0.01). CONCLUSION: Our study demonstrates that identification of select constellations of findings using abdominal sonography, in addition to focused US examination of the right lower quadrant, can improve sonographic diagnosis of perforated appendicitis in the pediatric population.

Free-breathing contrast-enhanced T1-weighted gradient-echo imaging with radial k-space sampling for paediatric abdominopelvic MRI.

OBJECTIVE: To compare the image quality of contrast-enhanced abdominopelvic 3D fat-suppressed T1-weighted gradient-echo imaging with radial and conventional Cartesian k-space acquisition schemes in paediatric patients. METHODS: Seventy-three consecutive paediatric patients were imaged at 1.5 T with sequential contrast-enhanced T1-weighted Cartesian (VIBE) and radial gradient echo (GRE) acquisition schemes with matching parameters when possible. Cartesian VIBE was acquired as a breath-hold or as free breathing in patients who could not suspend respiration, followed by free-breathing radial GRE in all patients. Two paediatric radiologists blinded to the acquisition schemes evaluated multiple parameters of image quality on a five-point scale, with higher score indicating a more optimal examination. Lesion presence or absence, conspicuity and edge sharpness were also evaluated. Mixed-model analysis of variance was performed to compare radial GRE and Cartesian VIBE. RESULTS: Radial GRE had significantly (all P < 0.001) higher scores for overall image quality, hepatic edge sharpness, hepatic vessel clarity and respiratory motion robustness than Cartesian VIBE. More lesions were detected on radial GRE by both readers than on Cartesian VIBE, with significantly higher scores for lesion conspicuity and edge sharpness (all P < 0.001). CONCLUSION: Radial GRE has better image quality and lesion conspicuity than conventional Cartesian VIBE in paediatric patients undergoing contrast-enhanced abdominopelvic MRI. KEY POINTS: • Numerous techniques are required to provide optimal MR images in paediatric patients. • Radial free-breathing contrast-enhanced acquisition demonstrated excellent image quality. • Image quality and lesion conspicuity were better with radial than Cartesian acquisition. • More lesions were detected on contrast-enhanced radial than on Cartesian acquisition. • Radial GRE can be used for performing abdominopelvic MRI in paediatric patients.

Relative distribution of pertinent findings on portable neonatal abdominal radiographs: can we shield the gonads?

BACKGROUND: Shielding of the gonads is a dose-saving strategy in pediatric radiography and its use is the law in New York and the majority of other states. However, routine use of gonadal shields is controversial because of concerns that important diagnostic information can be obscured. OBJECTIVE: The purpose of this study was to assess the frequency and spatial distribution of key findings on portable neonatal abdominal radiographs. MATERIALS AND METHODS: We reviewed the 2,544 portable neonatal intensive care unit anteroposterior abdominal radiographs performed in 2010 at a university medical center, of which 962 were inadequately shielded. These 962 radiographs were reviewed by pairs of pediatric radiologists for the presence of findings in different regions, including bowel abnormalities, pneumatosis, free air, inguinal hernias, osseous abnormalities, and catheter/tube tips. RESULTS: The fewest pertinent findings were present below the level of the sacrosciatic notches (n = 181, 18.8%). Of the 853 abnormalities below the level of the iliac crests in our cohort, six were isolated to these regions, whereas others had concomitant abnormalities more superiorly. Of 35 radiographs with pneumatosis or suspected pneumatosis in the pelvis, 33 had pneumatosis in more superior regions. Suspected free air was never isolated to the pelvis. Osseous abnormalities were only present in the pelvis below the sacrosciatic notch, and 37.5% of lower extremity catheters terminated below the level of the sacrosciatic notches. CONCLUSION: Pertinent findings on neonatal intensive care unit abdominal radiographs are rarely isolated to the pelvic regions.

Gorham-Stout disease and generalized lymphatic anomaly--clinical, radiologic, and histologic differentiation.

PURPOSE: Gorham-Stout disease (GSD) is a rare vascular disorder of lymphatic origin characterized by progressive osteolysis. Generalized lymphatic anomaly (GLA) is a multisystem disorder that also commonly affects bone. We hypothesized that Gorham-Stout disease is different from other osseous lymphatic anomalies. We proposed to discriminate these entities by analyzing findings on skeletal imaging. METHODS: Clinical data, imaging studies, and histopathologic findings were retrospectively reviewed in patients presenting to our Vascular Anomalies Center with lymphatic anomalies of bone. FINDINGS: Within a cohort of 51 patients with lymphatic disorder and radiological evidence of bony involvement, two distinct categories emerged. Nineteen patients met the imaging criteria for GSD: progressive osteolysis with resorption and cortical loss. Thirty-two were categorized as GLA: Discrete radiolucencies and increasing numbers of bone affected over time, but without evidence of progressive osteolysis. The ribs were the most common site in both groups, followed by the cranium, clavicle, and cervical spine in GSD, and thoracic spine, humerus, and femur in GLA. Fewer bones were involved in GSD, with relative sparing of the appendicular skeleton. Associated infiltrative soft tissue abnormality was seen in 18 in GSD, but only six with GLA. Macrocystic lymphatic malformations were identified in 14 with GLA, but none with GSD. CONCLUSIONS: There are significant radiological differences between GSD and GLA, although there are some overlapping features. The major distinguishing characteristic is the progressive osteolysis seen in GSD. Findings suggestive of GLA are more extensive involvement, particularly of the appendicular skeleton, presence of discretemacrocystic lymphatic malformations and visceral organ lesions.